My 1985 peugeot elan. My first real bike as a kid. Been hanging up in the garage for twenty years. Resurrected this summer. Had to redish and respace the rear wheel.
The forks are cheap superstar carbon ones. It does seem to float down sections of single track that I ride on a rigid 26er. The bigger wheels really do same to be advantageous. Plus I like the immediacy of the power transfer.
I've gone the other way. Full suss to rigid single speed. The biggest thing for me was the inefficiency of the suspension. Put you foot on the pedal on a rigid SS and the bike moves. Do the same on a front or full suss and the suspension will compress before the bike moves. I guess I like the immediacy of the power transfer.
To be honest you'll gain no advantage in racing on or off road. It's pure vanity unless you regularly receive deep tissue sports massage, then I would seriously recommend it.
I actually started my solo on a Specialized Epic and ditched it for my rigid Scandal 29er after the first lap. I felt like it wasn't very efficient with all that suspension. The bigger tyres definately helped on the muddy bits along with the gears and big wheels I could just winch myself through the mud.